Development of a ballistic model of combat groin injury.

Background: The current leading cause of death to troops in Operations Enduring Freedom results from improvised explosive devices. The need for accurate models of combat trauma in research is an ever present challenge and crucial to our efforts to save the lives of our injured troops. Current swine models of groin injury use a scalpel to create the wound, which provides for a controlled environment but limits the resemblance to real combat injuries. We sought to develop a reliable ballistic model of fragmentation injury that will allow for new research and training opportunities in the field of combat casualty care.

Methods: A jet remote opening device was developed to inflict a fragmentation injury to the groin of 20 anesthetized swine. Laser positioning ensured alignment. After hemorrhage, subjects were treated with standard resuscitative measures and monitored for 180 minutes to determine survival.

Results: Subject survival was 95% at 3 minutes postinjury and 75% at 180 minutes. Survival rates were similar to actual survival data collected from Operations Enduring Freedom (p = 0.993). Blood loss during initial hemorrhage averaged 15.4 (±6.0) mL/kg. No instances of peritoneal violation by the shrapnel fragments were revealed on necropsy.

Conclusions: We developed a ballistic mechanism of injury in a model that replicates improvised explosive device-created wounds. The injury was reliably reproduced in each subject, with survival rates equating those of real casualties. We think that this model represents a true effectiveness model of injury that opens the doors for advanced research endeavors in combat casualty care.